Conventionally, there is a commonly-known air conditioning apparatus that includes one outdoor device to which an AC power supply is connected, and a plurality of indoor devices connected to this outdoor device. In the air conditioning apparatus as described above, a technique has been proposed to limit the power supply to the outdoor device during the operation standby period in which both the outdoor device and the indoor devices do not operate.
As an example, Patent Literature 1 discloses an air conditioning apparatus that stops the supply of power to an outdoor device during standby. The problem of Patent Literature 1 is “to provide an air conditioning apparatus that is capable of reducing reactive power consumption in an outdoor device when this outdoor device is on standby while indoor devices are in operation”. In Patent Literature 1, there has been disclosed a technique “an air conditioning apparatus 1 including indoor devices A2 and B3, and an outdoor device 4, where the indoor devices A2 and B3, and the outdoor device 4 are connected by three cores that are a power-supply line 14, a power-supply signal common line 15, and a signal line 16, and power having been supplied from a commercial power supply 13 to either the outdoor device 4 or the indoor devices A2 and B3 is supplied to the other through the power-supply line 14 and the power-supply signal common line 15, wherein the outdoor device 4 includes an inrush-current prevention relay B18 and an outdoor relay B22, each of which connects or disconnects the commercial power supply 13 to or from an outdoor rectifying unit B25 for an outdoor control unit 29, and an inrush-current prevention relay A17 and an outdoor relay A21, each of which connects or disconnects the commercial power supply 13 to or from an outdoor rectifying unit A24 for an inverter circuit 28, and wherein a noise filter 23 is positioned closer to the outdoor rectifying unit A24 relative to the inrush-current prevention relay A17 and the outdoor relay A21”. That is, according to the technique in Patent Literature 1, a supply of power to the outdoor device is interrupted by the relays during the operation standby period, and therefore power is supplied only to the indoor devices so as to achieve power savings. Also, at the time of resuming the operation, the relays are operated to supply power to an outdoor-device control unit via the indoor devices, thereby immediately resuming the operation from standby.